Professional Education Services Group, LLC (PESG) is the largest substitute pooling provider in the Great Lakes Region. PESG, home of www.subpass.com, has created a solution that ties together the dispatching process, the payroll process, and the end-use district billing process that systematically incorporates the needed cost accounting functionality completed on a paperless architecture. PESG is dedicated to bringing well thought-out, end-use solutions through the ISD/RESA that bring value-added savings and functionality to the district(s) that makes sense. Substitute Pooling Provider.